Fuzz face volume issues

[bagudan]

Hi.
I made a fuzz face from this layout, using the standard values
http://www.aronnelson.com/gallery/main.php/v/Richard-Boop-RLBJR65/album84/FFace.gif.html
I also used mathed ge´s from smallbear. (3ax31c)

The fuzz is nice sounding, but I think it lacks volume boost. Also when i roll back the guitar volume pot the slightest bit, the distortion almost dissapears (unlike other fuzzes i´ve built)
Then I changed the 470 r resistor to 1k, and installed a 20 k trimmer instead of 8,2k. I can easily dial in 4,5 volts on q2´s collector, but still not enough boost, and still problems when rolling back the volume pot on guitar.
Voltages are.
Q1.
c: 0,45v
b: 99mv
e: 0

Q2:

c: 4,58v
b: 0,36v
e: 0,35v

Any Ideas?
-Kasper

[petemoore]

Q1.
*c: 0,45v
b: 99mv
e: 0

Q2:

c: 4,58v
*b: 0,36v
e: 0,35v
  Probably a typo, Q1c and Q2b should be connected/

[bagudan]

you´re absolutely right. Just measured them again....theyre both reading 0,49 volts

[joegagan]

you can split the resistor that biases q2 and take the output more directly from q2's collector. try two 10 k trimmers, put your output at the junction of the two, balance the two till you get -4.5 v and a signal level you like.

some people also put a 100k volume pot in place of the 500k for more output.

or, add a third gainstage for more output. this is especially helpful if you use smaller than stock input caps on the ff

[bagudan]

I´ll be trying a 100k for the volume control tonight when I get home.  This may increase output, but will it solve the problem with the guitars volume pot?
I´ve made an easy face once: When I roll back the guitars volume pot on this one, it´s easy to dial in the right amount of fuzz...it cleans up very well. I can almost turn the volume completely down, and still plenty of output.

On the stock fuzz face I´m debugging now, The fuzz almost dissapears when I roll the guitarpot back just a little?

[zombiwoof]

I´ll be trying a 100k for the volume control tonight when I get home.  This may increase output, but will it solve the problem with the guitars volume pot?
I´ve made an easy face once: When I roll back the guitars volume pot on this one, it´s easy to dial in the right amount of fuzz...it cleans up very well. I can almost turn the volume completely down, and still plenty of output.

On the stock fuzz face I´m debugging now, The fuzz almost dissapears when I roll the guitarpot back just a little?

One of the reasons people like Fuzz Faces is that they clean up when you roll the guitar volume back!.  Jimi Hendrix left his FF on most of the time, when he had the guitar volume rolled down a little it sounded like a slight OD, then he would roll it up that last little bit for raging fuzz.  This is the nature of the beast, and is considered a good thing.  It works best into a cranked amp, or into an OD into a clean amp to simulate going into a cranked amp.  Of course, if you are losing a great deal of volume when you roll it down, you need to dial in the bias to get it right.  If you want a fuzz that doesn't clean up when you roll down the guitar volume you should look into other types of fuzzes that don't clean up as severely.

Al

[bagudan]

Thanks for the reply. Iknow how it´s supposed to work. It´s kinda hard to explain. It doesn´t sound good when I roll back the volume.... like other fuzz faces do. This is my third layout with these transistors....maybe I´ll just try some others......just thought that a matched set would do the trick.
-Kasper